The present invention relates to collapsible bags for dispensing liquid products, and more particularly to collapsible bags having a surface that provides guiding or capillary paths for dispensing liquid products.
Various collapsible bags or containers are known in the prior art which are adapted to be filled with liquid contents and sealed and which allow their liquid contents to be suction withdrawn through their annular spouts or fitments. The walls of the bag are typically sheets of plastic, which are typically formed of polyethylene, polypropylene, nylon, or polyester. The liquid contents can be juices, milk, drink syrups or other liquids such as photoprocessing solutions, cleaning chemicals, or cocktail mixes. An example of these collapsible bags is the so-called xe2x80x9cbag-in-boxxe2x80x9d commonly used in the soft drink industry to deliver the drink syrup to the dispensing machine. The bags are fed into filling machines which uncap them, fill them with the syrup (or other liquid), recap them and box them. The boxes structurally support the bags during storage, shipment, and as they are being emptied. The bags are emptied through a spout in the bag accessible through a hole in the box and using a pump.
A plastic dip tube or dip strip disposed in the bag and secured therein so as to pass over the spout opening or to be secured to the spout opening assists in the withdrawal of the syrup from the bag. The strip prevents the bag from collapsing on the opening and closing it, and also guides the remaining quantities of syrup in the bag to the opening as the syrup continues to be withdrawn. The strip can be attached to the spout and/or to the inside wall of the plastic bag. Alternatively, the dip tube or dip strip can be attached to the perimeter seal of the bag. Examples of dip tubes or dip strips and their collapsible bags are shown in U.S. Pat. No. 4,286,636 (Credle), U.S. Pat. No. 4,601,410 (Bond), U.S. Pat. No. 5,647,511 (Bond), U.S. Pat. No. 5,915,596 (Credle), and U.S. Pat. No. 5,941,421 (Overman et al.) and in WO 99/46169 (Coca-Cola Company). (All of the patents and other publications mentioned anywhere in this disclosure are hereby incorporated by reference in their entireties.)
In addition to the separate manufacturing step required to make the dip tube or dip strip and the attendant material required to make the dip tube or dip strip, the application to the bag of a dip tube or dip strip requires yet another separate manufacturing step. Generally, after the spout is secured to the bag, the dip tube or dip strip is disposed in the bag by attachment to the spout, the inside wall of the bag or to the perimeter seal of the bag, or a combination of the above. This adds to the manufacturing time and expense. A further disadvantage of the strips, in addition to the cost of manufacturing them, is that they may become dislodged when the bag is filled at high pressure. A still further disadvantage of the strips is that they may create a back pressure and reduce fill rates.
Accordingly, disclosed herein is an improved collapsible bag which does not have a dip strip or dip tube and the problems associated therewith. Rather, the bag sheets have a unique construction which aids in the complete or near complete withdrawal of the syrup or other contained liquid. The sheets themselves have a surface xe2x80x9ctexture,xe2x80x9d which provides a guiding or capillary path for draining the liquid out the spout and which also prevents the sheets from closing off the flow to the spout during the suction of the pump.
One example of the textured surface is an embossed sheet of film with raised work in multiple designs and which can be mechanically embossed or ultrasonically embossed. Ultrasonic welding displaces a pattern into the surface of the film, thereby replicating a mechanically embossed (xe2x80x9cwaffle-likexe2x80x9d or other) pattern. The plastic sheets which comprise the walls of the bag can both be embossed or just one can be embossed. The sheets may be comprised of more than one layer of film, manufactured through co-extrusion or lamination. Other examples of xe2x80x9ctexturedxe2x80x9d surfaces which can be used are bubble wraps (cushion packaging), sealed pleats and folded constructions which run towards the spout. Further examples are disclosed in U.S. Pat. No. 4,964,540 (Katz), U.S. Pat. No. 5,549,944 (Abate) and U.S. Pat. No. 5,554,423 (Abate).
Also disclosed herein is an improved collapsible bag fitment. The bottom surface of the lower seal flange of the fitment preferably has seven concentric ridges or rings, twelve evenly spaced radial channels or grooves, and twelve gussets at the edge of the spout opening. An advantage to having radial grooves in conjunction with the concentric rings is the additional capillary or flow channel capacity created by using the full surface area of the flange.
An alternative embodiment changes the concentric rings to one or more spiral grooves to increase the flow to the spout bore using the same principle. In conjunction either with the radial grooves, concentric rings and gussets or with the spiral groove design or with the waffle pattern design, other features may be incorporated to enhance evacuation, including grooves on the inside bore of the spout and cross-bars spanning the spout opening.
Other objects and advantages of the present invention will become more apparent to those persons having ordinary skill in the art to which the present invention pertains from the foregoing description taken in conjunction with the accompanying drawings.